Eyelid swelling occurs when the area around your eyes fills up with fluid, making them appear puffy. Eyelid edema is the medical term for fluid retention in the eyelid. Swollen eyelids can result from a lack of sleep or may be a sign of a medical condition. Infections, trauma, and eye diseases can lead to swelling in the eyelid.

A swollen or puffy eyelid often goes away within 1 day. You can reduce the swelling with compresses, but how you treat a swollen eyelid can also depend on its cause. Causes can range from fluid retention to infection. If your eyelids are painful or tender to the touch, the cause is likely an infection.

Puffy eyes, also known as periorbital edema, are caused by fluid retention. They can be a symptom of many different things, including allergies, not getting enough sleep, eating too much salt, and medical conditions like thyroid disease. Genetics may also play a role, particularly as you get older and tissues under your eyes start to weaken.

Puffy eyes typically are simply due to aging, genetics, and possibly lack of sleep. But sometimes, swollen eyelids are mistaken for puffy eyes. When swollen eyelids occur suddenly, it might be a sign you have an underlying medical problem.